128 Bibliograpliical Notices. 



tho long period of time which elapsed between the issue of the 

 first and the final fasciculus are, we are told, twofold. In the first 

 place, a large portion of the author's time was taken up by official 

 and other duties, to which attention was imperative, so that only 

 spare hours (if such exist in the life of a busy naturalist) could 

 be devoted to the present volume. In the second place, collectors 

 were busy in obtaining and sending home consignments of reptiles 

 and batrachians from various parts of Central America, and it was 

 accordingly deemed advisable to await the arrival of as many of 

 these as possible. All these numerous collections added much to 

 our knowledge of the reptilian and batrachian species from the area 

 under consideration, and their geographical distribution ; but even 

 with these important additions the author has still to lament many 

 gaps in the available information. Apparently the districts best 

 known from a reptilian point of view are the plateau and highlands 

 round the city of Mexico ; but it is satisfactory to learn that the 

 Government of Costa Eica has been at special pains to explore its 

 territories and collect the fauna. 



One disadvantage inevitably connected with a work which 

 has been so many years in course of publication is that the earlier 

 portions must be somewhat out of date, for what was doubtless 

 first-rate zoology in 18S5 may not be in all respects so good in 

 1902. This disadvantage is fully acknowledged by the author 

 in the Introduction, where it is stated that much supplementary 

 labour and time will be necessary to correlate the earlier portions 

 of the work with the information which has been acquired and the 

 redeterminations which have been made subsequently to the dates 

 of their publication. This supplementary information, together 

 with a report on collections received too late for notice in the 

 volume before us, will, it is hoped, be issued in a separate form at 

 no very distant date. 



A total of 695 species is recorded in this volume, many of 

 which are described as new. In the case of the Reptiles only forms 

 of which previous accounts were unsatisfactory are described at 

 length ; but as regards the Batrachians this practice has been 

 abandoned in favour of a comparatively full history of each. In 

 accordance with the traditions of the ' Biologia,' as a whole, the 

 plates illustrating Dr. Giinther's volume are for the most part 

 beautiful examples of lithography, while the nine which have been 

 printed wholly or partially in colours are beyond praise. 



A special feature of the work is the attention bestowed on the 

 geographical range of the various species which come under review. 

 The tables, occupying eight closely printed pages of the Introduction, 

 which are devoted to the elucidation of this part of the subject, 

 afford by themselves some indication of the enormous amount of 

 labour and attention bestowed by the author on his task. 



The main scope of the work is, of course, the systematic description 

 of the cold-blooded land vertebrates of Central America and 

 Southern Mexico ; and the details of this can only be of interest 

 to students of this branch of zoology. Much more importance 



